Treatment of hydrocarbon oils



May'zl, 1935. v. IPATIEFF 2,001,910

TREATMENT OF HYDROCARBON OILS I Filed oct. 28. 1932 Paten-ted May 21,193s UNITED STATES Parent oFFica TREATMENT F HYDROCARBON GILSApplication October 28, 1932, Serial No. 640,123

6 Claims. (Cl. 196-10) This invention relates to the treatment ofhydrocarbon oils and refers more particularly'to the treatment of thelow boiling naphthas and gasolines produced from crude petroleums byfractionation -under conditions involving substantially no cracking.

In a more specific sense the invention has reference to a process fortreating said straight run gasolines to improve their quality withrespect to gum and color-forming compounds preseht and in a specificsense in regard to improving their antiknock value and increasing theiryield. The details of the process whereby these desirable reiiningeffects are -accomplished are given in the following specification.

In a general way the gasoline fractions present in crude petroleums andwhich may be removed therefrom by fractionation at moderate temperaturesand pressures reflect the character of the crude petroleum, i. e., theymay vary with the type of crude in the proportions of such hydrocarbongroups as parafns, olens, naphthenes, aromatics and the sulphur andnitrogen compounds which may be present. Although there are cases ofconsiderable divergence from this rule, it has been repeatedly notedthat the gasolines from parailinic crudes such as those from thePennsylvania and some of the Mid-Continent fields are highly parafinicand highly knocking in character. 'Ihe gasolines from the Mid-Continenteldcrudes and some of the Gulf crudes have an intermediate character inrespect to antiknock value, indicating possibly the presence ofrelatively higher percentages of cyclic compounds of the nature ofnaphthenes or of isoparaflins. Certa'h crude oils from the Pacic Coastproducing reas and some Texas fields yield gasolines of comparativelyhigh antiknock value, owing to the cyclic character of the crude oils.These observations as to the variable character of straight rungasolines are merely adduced in a general way to show that differentgasolines or naphthas may require different degrees of treatnientaccording to the process of the invention to 45 be presently disclosedin order to render them up to the prevailing market standards forantiknock value.

The present invention comprises a process of treatment whereby thecharacter of the hydro- 50 carbons present in straight run gasolines isaltered in the direction of increased antiknock value.

The process furthermore effects a conservation oi' some of the wasteproducts of cracking processes which are caused to combine chemicallywith certain hydrocarbon groups in straight run gasolines so that theoverall yield of l product is increased by this synthetic step.

In one specic embodiment the invention comprises treatment ofhydrocarbon mixtures of the character of straight run gasolines witholens in the presence of sludge sulphuric acid to produce hydrocarbonswhich add antiknock value 'to the gasoline and at the same time toproduce other desirable treating eiects.

The term olefin as used within the concept of the present inventioncomprises any compound of carbon and hydrogen of open chain structureand containing one or more double bonds between carbon atoms. Thefollowing tabulation gives a few of the lower boiling members of theethylene series which consists of homologs of the base substanceethylene containing one double bond:

Table No. 1

Beginning with compounds of four carbonV atoms, the table shows that anumber of isomers are possiblecorresponding to different positions ofthe double bond and the presence of tertiary or quaternary carbon atoms,the number of possible isomers increasing as the number of carbon atomsincreases. From these considerations it isv evident that for theethylene series alone a large number of diierent olefins may be employedeither singly or in admixture for condensation with paraiiinhydrocarbons according to the process of the invention.

The invention may further comprise the utilization of open chainunsaturated hydrocarbons of the acetylene or the diolefin seriescomprising such compounds as acetylene, butadiene,etc., and theirhomologs. While pure compounds of this character vand even ethyleneitself do not react readily even with aromatics in the presence ofsulphuric acid catalyst there is apparently some alkylation by thesecompounds when used in admixture with other oleflns as occurs in thecaseV of gases from cracking plants.

The reactions involved in treatments accordi to the process of theinvention are of considerable complexity owing to the large number ofhydrocarbon types represented in the "gasolines caused to join withbenzol to produce an alkylated may be considered. When gaseous prolyleneis passed into a well-stirred mixture of benzol and concentratedsulphuric acid in proper proportions, the propylene is apparentlysulfonated at first to prodce a monopropylsulfuric acid, and there -areindications that the benzol may be sulfonated to some extent. 'Ihesulphuric acid derivatives then react to form a propylated benzol andregenerate to a large extent the sulphuric acid so that the net resultof the reactions is expressed by the following equations which show theformation of monoand di-isopropyl benzol:

C H6 H H2804 C C H `C H 2) Prowlene Beienzoll Monos-isoproiyfbenzol2C3He' -i- CH CH4'(CsH7)2 The relative proportions of the monoanddiderivatives will depend upon such factors as the relative proportionsof the two hydrocarbons employed, the rate of introduction of thepropylene into the acidaromatic mixture, the strength of the acid andparticularly the temperature which in the majority of cases of thisAcharacter is best maintained at at least atmospheric temperature tominimize loss of olens by polymerization. In the above reactionspropylene represents any of the homologs of ethylene, although ethyleneitself is not specially reactive. Similarly benzol represents any of thearomatic series of hydrocarbons and may also typify the polynucleararomatics such as naphthalene and anthracene. However, the proportion ofthese polynuclear aromatics is undoubtedly very small in straight runggoolne fractions which commonly boil under The reactions given above inconnection with oleflns and aromatics are obvious and readilyunderstandable to those versed in organic chemistry. However, itisadvanced as a particular fea ture of the -present invention thatunusual and unexpected results have been obtained when treatinggasolines with olens and olen -mixtures in the presence of sulphuricacid when' the gasolines are ofa paraflinic character as produced fromPennsylvania crude oils and contain substantially no hydrocarbons of adistinctly aromatic character though possibly a considerable percentageof naphthenes. Owing to the diculties of exact analysis in the case ofhydrocarbon oil mixtures only a limited amount of data is available onthe subject of the proximate composition of gasolines, but considerablequalitative and some semi-quantitative experiments have indicated thatthe so-called paraflinic gasolines may consist not only of normal orstraight chain parains but also to a large extent of so-called iso orbranched chain parallns and cyclic compounds of asaturated orpartiallysaturated character such as the naphthenes and mixed alkyl derivativesthereof. The course of the reactions which lead to the improvementsnoted inA the case of straight run paranic gasolines when `treated bythe process of the present invention may consist in rearrangements amongthe substituting groups either in the open chain or closed chainhydrocarbons, or it may comprise the direct addition of olens to centralcarbon atoms in the paramnic ing process and other chains. Suchreactions cannot be closely followed owing to the diflicultiesin-'securing reliable analytical data.

'I'he following equations in addition'j-:tof those previously givensuggest further reactions which may take .place when olens are contactedwith straight run kgasolines in the presence of sulphuric acid underregulated conditions. In the case of a straight chain paraiin such aspentane, the following equation expresses a possible reaction:

CaHs *i* CsHlz CzHf'CsHn Propylene Pentaue Iso-propyl pentane Owing to'the observed increase in antlknock value which occurs many times in thealkyla'tion of straight run gasolinesaccording to the process ofthe'invention it 'is probable that at least some of the methyl or otheralkyl groups attach tofjtlre carbon chain in a central position sothatgisq: compounds are formed, since itknowii that hydrocarbons ofhigher antiknock value are tained when the carbon atoms are arrangedmore' compactly.

The equation given below suggests a- 'reaction which might be presumedto takeplace'betwee'n an olen and a naphthene or apartially' hydro,-vgenated aromatic of a mixed or terpenelike character:

Propylene Dihydrobenzol Dihydro isopropyl beuzol The foregoingsuggested. reactions, merely indicate possible trends and many other andmore complicated reactions may occur owing to the possiblity of theshifting of labile hydrogen atoms and alkyl groups such as methyl,ethyl, propyl, etc. v l A feature of the present invention is thatsludge acids resulting from the treatment of petroleum products, crackeddistillates, gases. from a crackproducts containing ele-ns and aromatichydrocarbons andthe like,;is 'employed as a catalyst and/orpolymerizingagent in the process. When sulphuric acid isA used tocatalyze reactions of the general character just described as occurringbetween oleflnsand other classes of hydrocarbons itsstrength mustbecarefully controlled and the temperature at whichfthe reactions areconducted must be held below a cer-g tain point if best results are .tobe secured-in the production of yields of products of the-desiredboiling range and quality. For example, inthe reactions betweenpropylene and benzol-just-de, scribed best results'are obtained if thetemperaf ture is maintained in the neighborhood of Qi C. When conditionsare such that the reactions leading to the formation of alkylderivatives of drocarbons predominate, it would appear that the initialstage of the reactions corresponds to theformation of sulphuric acidesters of o lelns and in compounds corresponding to sulfonicacids ofbenzol, which further react toform the-alkylated hydrocarbon andregenerate the .sulphuric acid. When sulphuric acid overa certain -limitstrength is employed, .temperatures areallowed to rise, or there is alack of intimate con? tact between the reacting constituents, therefisan increased tendency toward the formation of polymers of the olen's.This is particularlynd. ticeable .in employing oleflnic' hydrocarbonswhich occur in gases from cracking. processes since there are numeroustypes of olens .of highly unsaturated` character `present'. whosepolymers are of a gummy ortarry character .and

hence undesirable in the alkylated product which is primarily intendedfor use as a blending material to improve the antiknock characteristicsof motor fuel. Furthermore, unless conditions are kept within narrowlimits, there is a tendency for the formation of highly alkylatedhydrocarbons which may contain, for example, three or four substitutinggroups and which are of too high boiling character to be used ingasoline without unduly increasing its end boiling point.

It has been found that if sludge acids are employed in place of freshacid that the conditions of operation in alkylating hydrocarbons toproduce gasoline boiling range compounds admit of considerably greaterlatitude. There is less tendency toward the formation of gummy polymersor too highly alkylated compounds and owing to the more selective andmoderate nature of the reactions there is a decreased tendency towardexcessive temperature rise due to heat of reaction, and properconditions of treatment are more easily maintained in practice.

The term sludge acid" as used in the present specification may refer toany of the partly spent acids used in conducting treatments upon any ofthe miscellaneous oils treated in connection with the refining ofpetroleum, and it also includes in its meaning sludges which may beproduced in alkylating hydrocarbons with oleiins where fresh acid wasemployed, the last named class being in a sense recirculated acid. Inother words the invention comprises the use of sludges resulting fromthe sulphuric acid treatment of such miscellaneous oils as gasolines,both cracked and'straight run, naphthas, kerosenes, lubricating oils,etc. Since the object in usingA sludge acid is to catalyze the desiredreactions by acids diluted by soluble organic products rather than bywater, it is also comprised within the scope of the invention tosynthetically produce a sludge acid of desired characteristics byproperly blending a sludge acid with fresh or unused sulphuric acid toproduce a reagent of the desired activity. Obviously this procedureadmits of the production of a large number 'of reagents of propertiesvarying generally with the percentage and strength of free sulphuricacid present and while a number of alternatives are possible it is to beunderstood that they are not necessarily equivalent in their action.

lThe process of the invention is advantageously employed in connectionwith the utilization of the olelns in the gases produced as a by-productof oil cracking processes whose primary object is the production ofgasoline. The amount of gas produced in such processes varies generallywith the intensity pf cracking conditions and the olenic content of suchv4gases is frequently very high, sometimes running i0 to 50% by volumein the case of gases produced in high temperature-low pressure vaporphase cracking proc-- esses. Such gases contain large amounts ofethylene, propylene, butylenes, and amylenes though usually propylenepredominates, this particular olen frequently constituting as high as30% of the total gas mixture.

According to the process of the invention individual olefins or mixturesof oleiins and other hydrocarbon gases vsuch as those present in gasesfrom oil cracking processes are contacted with reactive hydrocarbons inthe presence of sludge acid. While the process is not limited to the useofI any `particular type of apparatus or plant arrangement it willassist in deiinng its character to describe an operation in connectionwith one arrangement of inter-connected elements which may be employedand for this purpose the attached drawing is provided which showsdiagrammatically and without reference to any particular scale, anarrangement of apparatus which may be employed.v

Referring to the drawing, the essential features of the plant shown areseen to be a source of supply for olefin-containing gas, aromatic liquidand sludge acid, chambers in which the gas and liquids are reacted inthe presence of the acid, settlers for separating the alkylated productfrom partly spent acids and neutralizing and washing tanks. The lastnamed are not a special feature of theprocess as the lneutralizing andWashing of products from acid-treatments is well established in the artand, furthermore, the layout shown provides'.- no means for redistillingthe puried'product though this may be done if and when necessary.Obviously the exact type of mixer for liquid hydrocarbon, acid and gaswill be modified to obtain best results in any given case and thedetails of construction may be altered in accordance with special needs.However, `the operation to be described is sufiiciently illustrative.

In the drawing shown an Glenn-containing gas such as the mixtureproduced from an oil cracking process is introduced to thesystem througha line I containing control valve ,2, line l having a branch line 3containing control valve 4. It is assumed for the purposes of thepresent discussion that the gas is under suicient pressure as it comesfrom a cracking plant so that pumping means are not necessary. An inletgas pressure of about loll pounds may be desirable in processes of thepresent character as there is considerable diilerentialp encountered inthe flow through the apparatus and the reactions are further assisted bypressure as will be later developed. In the present set-up, line 3conducts the gas to a primary reactor 5 while line l serves to conductit to a. secondary reactor V6'. The reactors'are provided with sprays-55 and 58 respectively and alsov superimposed perforated plates 56,-51, 59 and Silas shown to break up the oil and acid into a fine spray orinist which is thus brought into intimate Contact with the gas, thereaction taking place with all constituents owing downwardly.

4In the arrangement shown the order of the reactors may be reversed,since the acid, gas and oil lines are manifolded but for purposes of thepresent description reactor 5 will be considered as the primary reactorin which the inlet gas rich in olefins is contacted with freshhydrocarbon liquid in the presence of partly spent acid,`whi1e theresidual gas from this primary operation is contacted with separateportions of hydrocarbon liquid in secondary reactor 6 in the presence ofstronger acid. The concurrently principle of treatment, which is shownas a feature of the process in connection with the drawing, while aconvenient and efficient mode of operation, is not an essential featureof the present invention, which may comprise operations of aoncetlirough orV batch character. The principle of concurrentlytreatment in connection with the present process may be applied in stillother ways than that shown, since there are three separate substancesparticipating in the general reactions, to wit, olefin-containing gases,hydrocarbon liquid and sulphuric acid. To enumerate some of the possiblecombinations it maybe stated that (1) gases and hydrocarbon liquids maybe directed counter-current to acid, (2) acid and hydrocarbon liquidsmay be directed counter-current to gases and (3) acid and gases may bedirected counter-current to hydrocarbon liquid. Any of these particularoperations are comprised within the scope of the invention and maybeutllized at particular times although for purposes of clarity 'thedescription of an \operation in which acid'is passed concurrently ofhydrocarbon liquids and gases is generally adhered to. 'I he incominggas isthus introduced to reactor 5 through line 3 while freshhydrocarbon liquid mixed with sludge acid is introduced from line I4.All supply tanks and receivers are shown in duplicate arrangementto'assist in assuring continuous operation of the process. Thushydrocarbon liquid may be taken by pump I3 from sup- 4ply tanks 1 or 8either through line control valve I or line I I' containing controlvalve I2 and discharged through line I4 containing control valves I5 andI6 into reactor 5 as shown. Line I1 containing control valve I8 providesfor the introduction of the hydrocarbon liquid into secondary reactor 6.Sludge acid from the reactions in the primary reactor 5 may be takenfrom either receiver 3l or 32 through line 33 containing control valve34 or line 35 containing control valve 36 respectively'and pumped bypump'31 through line 38 containing control valve 39 to line 4Icontaining controlvalve 42 and' thence to line I4 and spray 55. Thesludge acid catalyst may be continuously circulated to insure itsmaximum utilization and when its eifectiveness is reduced below aneconomical point by the gradual accumulation of solubleesters, etc.,-a

portion of it may be continuously or intermittently discharged throughbranch line 38' containing valve 39' and the necessary amount of make-upacid, either fresh or sludge, introduced from the primary sludge acidsupply. If desired or if `advantages are gained thereby, partly spentacid from the reactions in the secondary reactor 6, obtained from tanks43 and 44, may be recycled to the primary reactor 5, valve 54 beingentirely or partially closed and valve 52 being open at such times. Inordinary operations the sludge product from the secondary reactor willbe circulatedby way of line 53 containing control valve 54, line 26 andline I1 until its emciency drops below an economical point- To reducepolymerization and undesirable side reactions the products from thereactor are-discharged in toto through a cooling coil prior to theirseparationinto a sludge acid layer, alkylated liquid and unreactedgases. Thus a header 6I contains valves 62, 62', 63 and 63' and permitsthe utilization of cooling coils 64, 65 and 66 as may be found mostexpedient. Similarly a header 61 may receive cooled products from anyone t. o1' the three coolers and direct the cooled products to eitherone of settling tanks 10 and 13 by the proper manipulation of valves 66and 69.

gas, hydrocarbon vliquid andsludge 'acid from the primary reactorseparate, the gas being -released through line 16 containing controlvalve 11 to line I leading t0 secondary'reactor 6. 'I'he liquid productshown as layer 1I may as desired be recirculated to the primary reactor,further. treated in the secondary reactor or withdrawn from the processfor neutralizing and washingas a nal product. In the first case a pump90 may withdraw the liquid layer through line containing a control valveand return the partially alkvlated liquid to the primary reactor by wayof line 9| and valve 9 containing 92, line 9|' and valve 92land line I4.When the partially alkylated liquid products from the reactor are to betreated in the secondary reactor, valve 92' is closedand the liquidproceeds to the secondary reactor by way of lines 26 and I1. zIn theevent that further alkylation is .not desired the liquid product may bediverted into line 93 containing control valve 94 and thus through line95 containing control valve 96 (whlchserves a similar plu'pose for thecorresponding material in settling tank 13) into neutralizing` tank 91to be laterdescribed. Partly spent acid from settling tank 16 shown aslayer 12 may be drawn to intermediateaccumulators 3| and 32 through linel0 containing control valve 87| or line 82 containing control valve 83respectively as may be expedient. When the sludge from this stage -is tobe further used, pump 31 is used for recirculating the first stagesludge acid into reactor 5, the stream being, diverted through line 4Icontainingl control valve 42, valve 40 being closed. l

In secondary reactor 6 according to the'. flow at present beingdescribed fresh. or partly alkylated hydrocarbon liquid iscontactedwith'the olefin-containing gas from the rst reactor in thepresence of sludge acid of relatively/.greater activity. The mainadvantage gained by this operation is that more acid may be used and ahigher rate of .alkylation effected without inicreased tendency' towardpolymerization among the oleflns, since these no longer comprise themore readily reactive members which were lost in the primary reactor.Thus sludge acid from a source outside the processmay be taken fromsupply tanks I9 or 20 through line 2| containing control valve 22 orline. 23 containing control valve 24 respectively and pumped by pump 25through line 26 containing control valves 21 and 28 into secondaryreactor 6. The products of this second stage in respect to the gas'orthe primary stage in respect to the acid may then be discharged througha cooler selected from those already described and passed to a settlingtank, in the present instance settling tank-13 which shows againalkylated hydrocarbon liquid" as layer 14'and sludge acid as layer 15.,The gas from this stage, being now` substantially free from reactiveolefns, is vented through line 16 containing control valve 19 and may beput to any use for which it is suited;

The sludge acid from the second'stagev is drawn from settling tank 13 totanks 43 and 44 through lines 84 containing control valve 85 or line 66-containing control valve 81 and may be further used in either of thereactors as its strength may indicate, though in the preferred mode ofoperation itwill be used inthe primary reactor 6 for reasons which havebeen already given.' Thus pump 49 may withdraw this acid from tank 4,3through line containing control valve 46 or from tank 44 vthrough line41 .containing control valve 48 vand discharge it through line 56containing control .valves 5I and v52. When this sludge acid is to beused in primary reactor 5, valves 5I and 52 will be open'and theacid-will pass directly to line I4. If used for any reasons in secondaryreactor `6 it may be diverted through branch line 53,containing` controlvalve. 54 and- .ultimately reach the reaction zone through line 'lli plyconsisting of sludge having a relatively high sulphuric acidconcentration.

The alkylated hydrocarbons from settling tank 'I3 may be passed to theneutralizing tank through line 95 containing control valve 96 eitheralone or in admixture with analogous products from settling tank 10 aspreviously described. Caustic soda of any desired strength may be takenfrom tanks 98 and 99 through line |00 containing control valve or line|02 containing control valve |03 and pumped by a suitable pump |04through line |05 containing control valve |06 from which it is allowedto pass downwardly counterflow to the ascending alkylated products. Theneutralizing tank is preferably so designed that the rates of oil andalkali can be adjusted and a substantially neutral or slightly alkalineliquid may be recovered from the top of the tank, this liquid passingthrough line containing control valve 2 into a water Washing tank H3. Toprovide for the removal of any accumulation of gases a vent line |26containing control valver |21 is provided in the top of the neutralizer.Line |01 containing control valve |08 permits the removal of spentneutralizing liquor. Line |09 containing control valve H0 is provided topermit the recirculation of a portion or all of the caustic solution aslong as it retains sufncient neutralizing power.

In the water washing tank the same counterflow methods may be employed,water being introduced through a line H4 containing control valve ||5 inthe form of a spray and the washed product drawn from the top of thetank through a line ||8 containing control valve I9 and passing eitherto final receiver |20 through line |20- containing control4 valve |2| orto receive |25 through line |22 containing control valve |23.

A commercial application of the process of .the invention is wellexemplified in the treatment of a straight run gasoline with the gasesfrom a cracking process. In such operations several modes of procedurewill present themselves to those conversant with commercial practices.In the simplest case a selected sludge containing approximately .75%sulphuric acid equivalent may be stirred into a stationary body ofgasoline in a batch agitator and a stream of olencontaining gasesbubbled through the suspension through a spray or other distributingmeans. It is usually preferable to have cooling coils` immersed in thereaction mixture so that excessive temperature rise is avoided.

The example involves the treatment of a Pennsylvania straight rungasoline with. the gases produced in cracking a fuel oil distillate fromthe same crude. The gasoline before treatment may have the followingproperties:

Gravity A. P. I 65.0 Initial boiling point 'F 100 overv at 152 over at180 I over at 1 200 40% over at 217 50% over at 234 60% over at 250A 70%over at 26,5 80% over at 288 90% over at' 322 End point (97.5%) 380 Whena blend of 90 parts of a test gasoline showing 67.5 octane number and 10parts of this gasoline is tested, an antilmock value of 52 octane numberis obtained.

This gasoline may be treated with an oleilnic gas mixture containingapproximately propylene by volume, this gas being produced inconjunction with cracking the fuel oil -distillate to produce gasoline.In the run 5.5 gals. of the straight run gasoline, 4.0 gals. of sludgeacid-and 1860 cu. ft. of the gas per hour may be injected into a mixingbox at the top of a tower through which the injected 'materials passdownwardly. As a result a volume of 235% of alkylated hydrocarbons maybe produced based on the volume of the original gasoline. The propertiesof the alkylated product may be as follows:

When this product is again used in 10%' blend with the reference fuel of67.5 octane number,

`the blend may test 83 octane number which indicates the remarkableimprovement effected by the treatment since the average boiling point ofthe product is considerably higher than the original gasoline and yetthe antiknock value is much higher as shown by comparing the o'ctanenumbers.

The blending uid thus produced may be distilled after a caustic washwith no change in color or odor or the development of sulphur compoundsdue to decomposition of soluble acid esters.

The foregoing specification has described and disclosed the general andbroad character of the invention and the example is'suillcientlyindicative of its value from a commercial standpoint. However, theinvention is not limited in scope to the exact details of thedescriptive material or the experimental data given.

I claim as my invention:

l. A process for the treatment of straight run distillate containinggasoline hydrocarbons to produce high anti-knock motor fuels therefromand to increase the volume thereof suitable for high anti-knock motorfuels, which comprises simultaneously subjecting said straight rundistillate and gases resulting from a cracking process to the action ofpreformed sludge acid clerived from the treatment of hydrocarbons withsulphuric acid, reacting components of the distillate with olefinscontained in the gases to form alkylated derivatives, and recovering theresulting liquid product.

2. A process for the treatment of straight run distillate containinggasoline hydrocarbons to -produce high anti-knock motorfuels therefromand to increase the volume thereof suitable for high anti-knock motorfuels, which comprises simultaneously subjecting said straight run dis-Y produce high anti-knock motor fuels therefrom and to* increase thevolume thereof suitable for the distillate with olefins contained in thegases to form alkylated derivatives, and recovering the resulting liquidproduct.

4. A process for the treatment of straight run distillate containinggasoline hydrocarbons to produce' high anti-knock motor fuels therefromand to increase the volume thereof suitable for high anti-knock motorfuels, which comprises simultaneously subjecting said straight rundistillate and gases resulting from a cracking process to the action ofpreformed sludge acid derived from the treatment of cracked' gases with.

sulphuric acid, reacting components of the distillate with oleiinscontained in the gases to form alkylated derivatives, and recovering theresulting liquid product.

5. A process for increasing the anti-knock value of light distillatescontaining a substantial quantity of hydrocarbons within the gasolinevboiling range, which comprises forming alkylated compounds in theristillate by reacting components of the latter with oleiins in thepresence of preformed sludge acid derived from the treatment ofhydrocarbons with sulphuric acid. 10

6. A process for increasing the anti-knockl value of 'light distillatescontaining a substantial quantity of hydrocarbons within the gasolineboiling range, which comprises treating the distillate with oleflnic gasin the presence of preformed sludge acid derived from the treatment ofhydrocarbons with sulphuric acid, reacting components of the distillatewith oleilns contained in the gas to form alkylated derivatives,

and recovering the'distillate containing the de- `2o rivatives thusformed.

VLADIMIR IPATIEFF.

